List of top Physics Questions on Kinetic Energy asked in Haryana PMT

A large number of liquid drops each of radius a coalesce to form a single spherical drop of radius $b$. The energy released in the process is converted into the kinetic energy of the big drop formed, the speed of the big drop is

A circular ring of mass $ m $ and radius $ r $ is rolling on a smooth horizontal surface with speed $ u $ . Its kinetic energy is :